Use upper constraints from opendev.org

tox_install.sh uses curl w/o -L switch so it fails to account for
redirects that are now in place for backward compat with
git.openstack.org.

Use proper new location of upper constraints instead.

Change-Id: Ic4ad019197b3a5655bd0b8599931792740d0a516
Related-Issue: PROD-29707
1 file changed